The present invention relates generally to an apparatus for printing on a web of film. More specifically, the present invention relates to an apparatus for providing a web of foil to be utilized to print of a web of film.
It is known to print on a web of plastic film utilizing foil and a printing member. Foil refers to the media utilized to print on plastic film and typically includes a surface having a pigment that is transferred onto the film through the application of heat. The foil acts somewhat like a template, e.g., carbon paper, to provide means for printing on the film.
It is also known to package products, such as liquids, food stuffs, and other materials, in flexible containers created from a web of film. There are a variety of different types of packaging machines that can be utilized to package a product in a flexible container. One such machine is a form, fill, seal packaging machine which can be utilized to package a product in a flexible container. Form, fill, seal packaging machines are utilized to seal, for example, pharmaceuticals, dairy products, wine, food stuffs, cosmetics, and other products in flexible containers. A form, fill, seal packaging machine provides an apparatus for packaging these products in an expedient manner.
In one type of form, fill, seal packaging machine, a web of film is unwound from a roll of film, and fed into a packaging machine wherein it is formed, filled, and sealed. To this end the web of film is passed over a former or mandrel that forms the film into a tubular shape. To effect the tubular shape, the film is folded longitudinally and heat-sealed along abutting longitudinal edges. The tubular-shaped film is then passed around a tubular fill system that deposits the product to be packaged into the tubular-shaped film.
To create individual packages (hereinafter "bags"), the web of film is sealed across its width to form side seals. These side seals are typically created by a sealer that creates the second seal for one bag while making the first seal for the second bag. Usually, after the side seals are created, the web of film is severed between the seals to create individual bags.
In packaging certain products, it may be desirable to print on the web of film to provide means for identifying the product, instructions, or the like. In the pharmaceutical area, for example, many products include what is referred to as label copy. Accordingly, in packaging pharmaceuticals in flexible containers constructed from a web of film, it is known to print on the web of film to provide label copy for the housed product. To this end, a web of foil is utilized to generate an image on the web of film in cooperation with a printing member for transferring the pigment on the foil to the web of film. Typically, the web of film is printed on prior to being formed in the form, fill, seal packaging machine.
In use, the web of foil is fed between the web of film and the means for printing. The web of foil is fed from rolls on which the foil has been previously wound when it was manufactured. One of the problems encountered in printing on film, especially in high speed form, fill, seal packaging machines, is that a roll of foil must be replaced approximately 5 to 6 times per 8 hour operating shift of the packaging machine. Because changing a roll of foil typically takes approximately 10 minutes, this results in a down time of approximately 1 hour for the packaging machine per shift.
Indeed, in certain printing operations, it may be desirable to have more than one printer so that multi-colored images can be generated. Because the rolls of foil from which the images are generated, and from which foil is fed to the printers, will not be synchronized with respect to their lengths, the downtime of the packaging machine having such multi-printing stations will increase as much as two to three fold.
Accordingly, there is a need for an improved apparatus and method for providing foil so that a web of film can be printed on.